This invention relates generally to the art of observing an object space with radiation, and more particularly pertains to a technique for discriminating between different objects of varying shape and other characteristics which affect their reaction to illuminating radiation.
Standard radar and sonar techniques for discriminating between different objects (targets) is cumbersome. A narrow band radiation signal is directed at an object and the reflected radiation is used to determine range and velocity of the object. The narrow bandwidth of the radiation chosen is that with which the object reacts favorably as a reflector. The range and velocity information as to each object in an object space being observed is then used to discriminate one type of object from another. For instance, if a river channel is being monitored by sonar techniques, the position of various rocks in the channel are known. A moving object such as a large fish or ship can then be detected because its range and velocity are different from those known objects (clutter) such as rocks in the shipping channel. This standard technique of discrimination among objects is complicated, however, since the information obtained from the clutter objects must be considered by an operator as to whether it indicates the presence of an object of interest each time the channel object space is observed with the radiation.
Therefore, it is a primary object of the present invention to provide a technique for discriminating among different objects in a radiation field of view with less complication and operator interpretation than is now required in present sonar and radar techniques.